No big deal, really, the device merely capable of producing the “heat and pressure” typical of any explosion.

Per Jacob Nergaard, assistant general secretary with NGO Norwegian People’s Aid, who has previously worked in bomb disposal, told Aftenposten that the attempt by the teenager was “amateur”.

“The attempt by the 17-year-old was amateur, but in a small room with many people it could be serious. Nevertheless, the question is whether he would have been able to detonate it, and even if he had, the result would have primarily been heat and pressure,” said Nergaard.

As is typical of teenage pranks, the explosive device had “nails taped to the outside”:

Meanwhile, broadcaster NRK has reported that the suspect has expressed support for terror group Islamic State (Isis) on social media by liking a photo of one of the organisation’s most infamous figures, Mohammed Emwazi, also known as “Jihadi John” due to the British accent with which the executioner speaks in videos released by the group.